Note 5 - Loans - Amortized Cost of Modified Loans (Details) - USD ($) $ in Thousands	12 Months Ended
	Dec. 31, 2023	Dec. 31, 2022	Dec. 31, 2021
Modified	$ 2,872	$ 11,946	$ 2,153
Extended Maturity [Member]
Modified	222
Rate Reduction and Term Extension and Payment Deferral [Member]
Modified	2,650
Commercial Portfolio Segment [Member]
Modified	$ 2,650	$ 6,115	$ 2,150
% of total loans	0.08%
Weighted average rate reduction	1.10%
Weighted average term increase (Year)	2 years 2 months 12 days
Weighted average payment deferral (Year)	10 months 24 days
% of total loans	0.08%
Commercial Portfolio Segment [Member] | Extended Maturity [Member]
Modified	$ 0
Commercial Portfolio Segment [Member] | Rate Reduction and Term Extension and Payment Deferral [Member]
Modified	2,650
Residential Mortgage Loans [Member]
Modified	$ 222
% of total loans	0.00%
Weighted average rate reduction	0.10%
Weighted average term increase (Year)	0 years
Weighted average payment deferral (Year)	2 years
% of total loans	0.00%
Residential Mortgage Loans [Member] | Extended Maturity [Member]
Modified	$ 222
Residential Mortgage Loans [Member] | Rate Reduction and Term Extension and Payment Deferral [Member]
Modified	$ 0